Discrete multipole dark solitons in saturable nonlinearity media with parity-time symmetric lattices Zhiwei Shi, Jing Xue, Zhu Xing, Yang Li and Huagang Li Eur. Phys. J. Plus, 132 2 (2017) 79 Published online: 16 February 2017 DOI: 10.1140/epjp/i2017-11348-5